Indicate whether each of the following compounds will gave an acidic, basic or neutral solution when dissolved in water. Clear All ammonium bromide barium nitrite barium iodide potassium bromide The pH will be less than 7. The pH will be approximately equal to 7. The pH will be greater than 7.

For each of the following types of reactions, write a general reaction formula in the symbolic form—for example, a + b → ab. single-displacement double-displacement synthesis decomposition

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Which fact represents evidence for the big bang theory?